1. Field of the Invention
The invention relates to methods for making nano-scale films and, particularly, to a method for making a nano-scale film with nano-scale particles.
2. Discussion of Related Art
A nano-scale film is a film that is constituted of nano-scale particles or that is a nano-monolayer film or a nano-multilayer film, which is in nanometer scale in thickness. Generally, the above-described film is also called a nano-particle film or a nano-multilayer film. As the nano-scale film has unique properties (e.g., optical, mechanical, electromagnetic, and/or sensitivity to gases and/or concentrations thereof), the nano-scale films have been widely applied in various fields, such as heavy industry, light industry, petrochemical, etc. Nano-scale films have been found especially useful in field emission electron sources, photoelectric and biological sensors, transparent electrical conductors, battery electrodes, absorbing materials, water purification materials, and related devices. Currently, conventional methods for making nano-scale films include a sol-gel method, a Langmuir-blodgett (L-B) method, electrochemical deposition, chemical vapor deposition, low energy cluster deposition, vacuum evaporation method, sputtering deposition method, molecular and atomic beam epitaxy, molecular self-assembly, etc. However, the above-described methods generally have complicated fabrication procedures. Thus, in use, such methods have proven less efficient than truly desirable. Furthermore, it is difficult to control the thickness of the nano-scale film in the above-described methods.
What is needed, therefore, is a method for making nano-scale film that is very simply and efficiently produced and whose thickness is easily controlled as a result of the production process.